1. Field of the Invention
The present invention relates generally to a display system for displaying a print image on screen, and relates especially to a display system disposed to a digital printer controller.
2. Description of the Related Art
Digital printing systems basically consist of a digital printer for outputting printed material (referred to as the “printout” below), a controller for the digital printer (referred to as simply the “controller” below), and a front-end computer for creating the data from which the printout is produced. The controller typically has a computer unit, input devices such as a keyboard, a mouse and so on, an auxiliary storage such as a hard disk for storing programs and data for printing, and a display device such as a liquid crystal display or CRT display. Using the front-end computer of this digital printing system, the user first compiles the text, drawings, symbols, photographs, pictures, and other information to create the data from which the printout is generated. This data is referred to as the “layout data” below. This layout data is then sent to the controller via a network. The layout data is then rasterized by the controller and converted to a bitmap image data format (“print data” below) that can be printed from the digital printer.
However, before the digital printer prints on paper, the print layout is typically confirmed by displaying a virtual representation of the printout on the display device in a so-called “print preview screen” by means of a “print preview” function. See, for example, Japanese Published Patent Applications 2001-10153 and 2002-55803. If the document to be printed contains more than one page, the printout is presented one page at a time on the print preview screen. There are various ways to change the previewed page, such as clicking buttons for showing the next or previous page with mouse, or dragging a scroll bar icon with mouse to change the displayed page continuously. The print preview screen may also have a page number input box so that the user can enter a particular page number and turn to the specified page.
A problem with this print preview screen, however, is that because the printout is presented one page at a time, multiple pages cannot be displayed at the same time so that the print layout can be confirmed while comparing the different pages. When the page number is to be printed in a specific position on each page of the printed document, for example, it is difficult to confirm if the position where the page number is printed varies on different pages because multiple pages are not displayed simultaneously in the print preview screen. It is also difficult to confirm from the print preview screen whether the print margins around the printing area of each page are the same on every page.
To solve these problems print preview screens that can simultaneously display multiple pages of the printed document, and print preview screens that display facing pages containing multiple pages on one sheet, are also known.
A problem with these print preview screens, however, is that when many pages are displayed simultaneously in the same screen, the per-page display area on screen becomes smaller and the text and others are reduced in size. As a result, comparing the print layout of each page is still not easy even though multiple pages are displayed simultaneously on the same screen. Furthermore, when consecutive pages are displayed with the screen split vertically so that the pages are shown in the top and bottom of the screen, the bottom part of one page and the top part of the next page can be easily compared because they appear adjacent on screen. The bottom of one page and the bottom of the next page cannot be easily compared, however, because they appear in non-adjacent areas on screen.